When paper-insulated cables are to be connected in a junction or a termination, it is known to apply a barrier layer over the insulating paper layers at the junction or termination accessories. The barrier sleeve protects the cable and provides a dry cable type interface onto which accessories for dry cables can be mounted.
An adapter capable of being installed in a single step is described in document EP 1 220 408.
That cold-shrink adapter comprises an insulating sleeve of silicone rubber, a conductive metal element constituted by a stocking of copper wires, a semiconductive layer of semiconductive silicone rubber situated between the insulating sleeve and the conductive metal element, and an outer protective sleeve covering the conductive metal element, in part. A support element enables that set of layers to be held in a radially-expanded state, with the support element being removable from said set of layers in order to cause the layers to shrink onto the cable or cables.
Once the adapter has been mounted, junction or termination accessories enclose the ends of the above-specified layers, covering the ends of the outer protective sleeve.
The problem raised by such an adapter is that the layers of rubber are not completely impermeable to moisture. When the junction or termination is installed in the ground and exposed to water, moisture penetrates slowly through these layers and is finally absorbed by the insulating paper of the cable or cables, which can lead to an electrical fault.
The Applicant has thus envisaged adding a fine and flexible metallized sheet compatible with cold-shrinking the adapter, between the conductive metal element and the outer protective sleeve, over a length longer than the length of the protective sleeve, the sheet projecting from both ends of the sleeve.
Nevertheless, it is found that even with a metallized sheet, such an adapter is not completely leaktight since, at the edges of the sheet, there remains a zone where moisture can infiltrate.